I'm not being stupid, you just change it. How ever it is installed, threaded on, sweated or compression fitting, remove and replace. I'm assuming water. There is another shut off valve further down the line. If it is the main shut off in the house, there is one at the meter. Shut the water off, drain the pipes and change it.
Shut off valve at the wall? Turn the main water line off and change it. How you change it would depend on what type it is and how it attaches to the pipe.
change the (pvc) valve
This depends what shut off valve is in question here. Where the leak is and what type of material is the shut off valve made of.
the hot water valve shut off valve shuts off the hot water. The cold water valve shuts off the cold water. ;()
Shut the water off at the main shut off where it comes into the house or at the meter and change the valve at the fixture. The valve at the fixture may be sweated on, compression, or threaded.
What to use to solder a shut off valve
An air-intake engine shut-off valve regulates air-flow to the motor, and operates as an emergency shut-off valve. There are also shut-off valves on water hoses, so shut-off valves really control the inflow of any liquid or gas.
where is the fuel shut-off valve on a 1998 4 runner?
The shut off valve.
It doesn't need a shut off valve. In fact only Ford Motor Company installs fuel shut off valves in their cars.
shut off valve filters in tank stopped up or the valve is bad.
A gate valve is positive shut off and used for on of off . A globe valve is for throttling